The proposed research aims to improve our understanding of discourse comprehension deficits often incurred by adults with right hemisphere brain damage (RHD) as a result of stroke. Among the most prominent impairments in this population is a difficulty comprehending material that supports or induces multiple, ostensibly competing interpretations. While these deficits can be quite socially handicapping, they are poorly understood, with conflicting explanations the rule. Two groups of adults, 50 with RHD and 45 without brain damage, will complete auditory sentence- and discourse-level comprehension tasks. Tasks will be designed to generate less explicit and more sensitive than usual indices of comprehension. One main goal of the proposed work is to test the Pl's 'suppression deficit' view of typical RHD deficits in comprehending material that supports competing interpretations, against influential theoretical alternatives in the lexical-semantic processing and social cognition domains. The proposal aims to (1) resolve conflicting hypotheses (suppression deficit vs. maintenance deficit) about RHD lexical-semantic deficits when processing sentences that contain words with alternative meanings or features; (2) test the claim of both the suppression and maintenance deficit positions that such word-level deficits will predict typical RHD discourse comprehension deficits; (3) test the hypothesis that RHD suppression deficits also will predict 'presumed' social cognition impairments (i.e., 'theory of mind' (TOM) deficits), as inferred from common discourse assessment tasks; (4) challenge the validity of the TOM-deficit attribution for RHD comprehension impairments, given various confounds in common TOM assessments; (5) test specific hypotheses about neuroanatomic bases of possible RHD lexical-processing and TOM deficits; (6) assess whether competing proposals can be reconciled with reference to within-hemisphere lesion location; and (7) evaluate the within domain generality of results with the same large sample of RHD adults, using multiple measures of word and discourse-level deficits. The results of the proposed investigations will advance theorizing in a nascent area of investigation and, by bolstering theoretical rationales for assessment and treatment, have eventual clinical implications for this understudied population.